The use of integrated air diffusers in combination with various forms of drop ceiling construction is well known. An integrated air diffuser for use with acoustic tile-type ceilings is described, for example, in my copending application Ser. No. 780,237, filed Mar. 22, 1977, now U.S. Pat. No. 4,135,441 entitled "Integrated Air Diffuser". In most such air diffuser designs, some means is provided to direct the flow of air discharged into the room in a particular pattern. Thus it is desirable that air flow extend substantially parallel to the ceiling and down the walls to avoid drafts and to obtain the desired heat distribution.